1. Field of the Invention
The present invention relates to a waste ink absorber which is equipped in an ink-jet recording apparatus having ink-jet heads to eject ink for recording, for controlling spreading ink flow due to blown up ink mist from ink preeject ports and spreading ink mist from a gap between ink pre-eject ports and the waste ink absorber, and also relates to the ink-jet recording apparatus equipped with a pre-ejected ink receiving device.
2. Brief Description of the Related Art
Various kinds of recording methods, for example, wire-dot methods, thermal methods, thermal transfer methods or the ink-jet method have been proposed as mountable recording heads for recording apparatuses to record on paper, cloth, plastic sheet and OHP sheet etc. (Hereinafter simply referred as xe2x80x9crecording paperxe2x80x9d).
Among these methods, the ink-jet methods, one of the non-impact methods with low noise to deposit ink directly on the recording paper by ejecting ink, are on the whole classified into continuous methods (including an electric charge controlling method and a spraying method) and on demand methods (including a piezo-electric method, a Spake method and a bubble-jet method).
In the continuous methods, ink is continuously ejected, where electric charges are charged to only required liquid droplets. Some of the charged droplets are deposited on the recording paper and remaining droplets are wasted. On the other hand, in the on-demand methods, since ink is ejected upon only requests for printing, ink is not wasted. However, in these method ink is ejected intermittently, responding frequencies in these methods are lower than responding frequencies in the continuous methods. A higher printing rate is realized by increasing ejecting nozzle number. Due to reasons mentioned above, most of the available recording apparatuses are employed on-demand methods. Since recording apparatuses equipped with ink-jet recording heads attain denser and higher rate recordings, they are practically used as output means for information processing systems such as printers as output terminals for copying machines, facsimiles, electronic type writers, word processors and work stations etc., or handy or portable printers for personal computers, host computers, optical disk devices and video recording devices etc.. Ink-jet recording apparatuses are modified so as to meet requirements in various applications described above.
Generally, a carriage for mounting a recording means (recording head) and an ink tank, a feeding means for feeding the recording paper and a control means for controlling these means are arranged in the ink-jet recording apparatus.
The recording head for ejecting ink droplets from a plurality of eject ports are serially scanned in a perpendicular direction (a main scanning direction) to a paper feeding direction (a sub scanning direction) during printing operations, while the recording paper is intermittently fed by a width corresponding to a gap between two neighboring printing lines during non-printing periods. This method where ink is ejected onto the recording paper in response to recording signals may be operated at lower cost and widely used as a calm recording method. When the recording head equipped with a plurality of nozzles for ejecting ink, arranged in series along the sub-scanning direction is used, printing lines corresponding to the nozzle number are recorded simultaneously by scanning the recording head over the recording paper one time. Which may realize printing operations with much higher rate.
However, in the above-mentioned conventional ink-jet recording apparatus, there is a significant problem that ink contamination, due to blown up ink mist from the ink pre-eject port and spreading ink mist from a gap formed between the ink pre-eject port and the waste ink absorber, is deposited the more in the recording apparatus as the more printing operations are executed, since a pre-ejected ink receiving device including the waste ink absorber does not control flowing ink mist.
The present invention is carried out in view of the above-mentioned problem, to provide a waste ink absorber, a pre-ejected ink receiving device and a platen for controlling the ink mist flow and also to provide an ink-jet recording apparatus equipped with these members.
In order to attain the above-mentioned objective, the waste ink absorber according to the present invention to which ink droplets from the ink pre-eject port directly coillide, is formed out of a material with rough density.
The waste ink absorber according to the present invention is formed out of a foamed material having foam cells less than 300/inch.
The pre-ejected ink receiving device according to the present invention is characterized that the waste ink absorber formed out of the material with rough density and an incident angle of the ink droplet against the above-mentioned waste ink absorber is acute.
Further the ink-jet recording apparatus according to the present invention where the above-mentioned pre-ejected ink receiving device is employed is characterized that an eject velocity of ink during pre-ejection is set slower than an eject velocity of ink during printing operation.
In addition the ink-jet recording apparatus according to the present invention where the above-mentioned pre-ejected ink receiving device is employed is characterized that a driving frequency of the pre-ejection is set lower than a driving frequency of printing operation.
And the ink-jet recording apparatus according to the present invention where the above-mentioned pre-ejected ink receiving device is characterized that ejected ink volume during the pre-ejection is set larger than ejected ink volume during printing operation.
The waste ink absorber, the pre-ejected ink receiving device and the ink-jet recording apparatus according to the present invention arranged in the above-mentioned way comprising: the waste ink absorber to which the pre-ejected ink droplet collides, is formed out of the material with rough density; the colliding incident of the ink droplet against the waste ink absorber is set acute; a space is arranged around a position where ink mist generated by the collision is flown up for floating or absorbing the ink mist; an exhausting port for discharging the ink mist and discharging path for leading the ink mist to the exhausting port are formed like a maze structure; turning around portions such as cul-de-sacs are formed in the discharging path; waste ink absorbers which receive the pre-ejected ink or the pre-ejected ink receiving device is arranged in a V shape; a shielding member of the pre-eject port arranged on a platen is protruded inside a compartment formed by the arrangement of the waste ink absorber or the pre-ejected ink receiving device where the shielding member is formed in a tapered shape; a thin plate is arranged around the pre-eject port at a side where the carriage moves after the pre-ejection and at a higher position than the pre-eject port for generating turbulent flows around the pre-eject port by the movement of the carriage; air vents formed around a position where the carriage reverses its moving direction wherein; an ink ejecting velocity of the pre-ejection is set lower than an ink ejecting velocity of the printing operation, an ink ejecting volume during the pre-ejection is set larger than an ink ejecting volume during the printing operation for reducing the flying velocity of the ink mist generated during the pre-ejection at the exhausting port having turn around portions.